The biggest problem for all of these techniques is font licenses. Adobe hasn't really spoken about their stance on using something like Cufón to render their fonts on the web. I tried to figure out Adobe's SLA, with respect to fonts over here.

This is a great opportunity for designers on the web. Fonts have been the weakest tool in the developers bag of tricks. Once the type foundries clearly state their position on this subject, a whole new world opens up for us.